A conventional optical microscope uses optical lenses to gather light from an illuminated object and provide a magnified image of that object to the viewer. An additional light source, that itself may require conditioning optics, is often used to illuminate the sample for the conventional optical microscopes.
Such conventional optical microscopes, however, may have drawbacks and disadvantages for specific microscopic applications. For example, when conventional optical microscopes are used to observe biological samples, the strong illumination power of the conventional optical microscopes may irreversibly degrade biological samples, e.g., living cells. This is known as photo-toxicity in the prior art. In addition, it is desirable for modern microscopes to be small, light weight, and free of moving parts, which conventional optical microscopes are not.
Thus, there is a need to overcome these and other problems of the prior art and to provide a compact, portable and robust lens-less microscope that has a high image resolution and a controllable illumination power.